Alternative sources include cord blood and HLA haploidentical donors. Cord blood has been an attractive source permitting immediate availability and possibly a lower rate of graft versus host disease (GVHD). However delay in engraftment, particularly after myeloablative conditioning, remains a significant disadvantage. Haploidentical transplants carry some of the same advantages with virtually all patients having immediate access to a suitable and willing donor in the form of a partially HLA matched family member. Furthermore the number of potential donors allows for donor selection based upon factors such as age, gender, KIR alloreactivity. Finally the donor is readily available for future cellular therapies such as donor lymphocyte infusion.